Wireless communication networks or radio communication networks may require a communication between a base station (BS) which may be a fixed station and a user equipment (UE) which may be a mobile station.
In a discontinuous reception (DRX) operation in a wireless communication network, the UE may be allowed to monitor discontinuously whether the BS transmits any information concerning the UE. DRX may improve the battery lifetime of a UE.
A radio resource control (RRC) protocol may be used by the wireless communication network and provide for connection establishment and release functions between the UE and the BS. A UE may be either in an idle mode or so-called RRC_IDLE state or in a connected mode or so-called RRC_CONNECTED state.
In the RRC_IDLE state, the UE may be configured to monitor a paging reception. Paging occasions (PO) may depend on a paging cycle. In the RRC_CONNECTED state, the UE may be assigned a DRX time cycle to receive scheduled information. The DRX time cycle may comprise DRX active time periods and DRX inactive time periods. During the DRX active time or DRX active state the UE may receive a physical downlink control channel (PDCCH). In the DRX inactive period the UE may not be required to monitor the PDCCH. The DRX inactive period may provide a sleep opportunity for the UE which allows saving battery life.
Regardless its DRX configuration, for example regardless its DRX time cycle, a UE in RRC_CONNECTED state may be still required to monitor paging reception. Paging reception monitoring may be required to detect and to apply system information (SI) modifications as well as notifications for earthquake and tsunami warning system (ETWS). Further information which may be required to be detected in paging messages is the commercial mobile alert system (CMAS).
The time periods of DRX active states may depend on the DRX cycle. Paging occasions may depend on the paging cycle. DRX cycle and paging cycle may not be adapted to each other. When a DRX active state and a paging reception opportunity or paging occasion are not aligned in time, a time where UE may be in a sleep modus, may be shortened and hence battery lifetime may be shortened as well. For this and other reasons there is a need for the present disclosure.